max5970 Maxim Integrated Products, Inc., max5970 Datasheet - Page 38

• Manufacturer Part Number: max5970
• Description: 0v To 16v, Dual Hot-swap Controller With 10-bit Current And Voltage Monitor And 4 Led Drivers
• Manufacturer: Maxim Integrated Products, Inc.

Figure 7. SMBUS/I
0V to 16V, Dual Hot-Swap Controller with 10-Bit
Current and Voltage Monitor and 4 LED Drivers
Both SCL and SDA idle high when the bus is not busy.
A master device signals the beginning of a transmission
with a START condition (see Figure 3) by transitioning
SDA from high to low while SCL is high. The master
38
SEND BYTE FORMAT
BLOCK WRITE FORMAT
S = START CONDITION
P = STOP CONDITION
RECEIVE BYTE FORMAT
BLOCK READ FORMAT
_____________________________________________________________________________________
S
S
S
S
SLAVE ADDRESS–
EQUIVALENT TO CHIP-
SELECT LINE OF A
3-WIRE INTERFACE.
SLAVE ADDRESS–
EQUIVALENT TO CHIP-
SELECT LINE OF A
3-WIRE INTERFACE.
SLAVE ADDRESS–
EQUIVALENT TO CHIP-
SELECT LINE OF A
3-WIRE INTERFACE.
ADDRESS
ADDRESS WR
ADDRESS
SLAVE ADDRESS–
EQUIVALENT TO CHIP-
SELECT LINE OF A
3-WIRE INTERFACE.
7 BITS
7 BITS
7 BITS
ADDRESS
7 BITS
2
0
WR
WR
C Protocols
1
0
WR
ACK COMMAND
0
ACK
ACK
DEPENDENT ON A SEND BYTE.
DATA BYTE–PRESETS THE
INTERNAL ADDRESS POINTER.
DATA BYTE–READS DATA FROM
THE REGISTER COMMANDED BY
THE LAST READ BYTE OR WRITE
BYTE TRANSMISSION. ALSO
COMMAND BYTE–
PREPARES DEVICE
FOR BLOCK
OPERATION.
SHADED = SLAVE TRANSMISSION
Sr = REPEATED START CONDITION
ACK
START and STOP Conditions
8 BITS
8 BITS
8 BITS
DATA
DATA
COMMAND BYTE–
PREPARES DEVICE
FOR BLOCK
OPERATION.
COMMAND ACK
8 BITS
ACK
ACK
ACK
SR
P
P
SLAVE ADDRESS–
EQUIVALENT TO CHIP-
SELECT LINE OF A
3-WIRE INTERFACE.
ADDRESS
7 BITS
COUNT= N
8 BITS
BYTE
WRITE BYTE FORMAT
WRITE WORD FORMAT
WR
1
S
S
ACK
SLAVE ADDRESS–
EQUIVALENT TO CHIP-
SELECT LINE OF A
3-WIRE INTERFACE.
SLAVE ADDRESS–
EQUIVALENT TO CHIP-
SELECT LINE OF A
3-WIRE INTERFACE.
ACK
ADDRESS
ADDRESS
7 BITS
DATA BYTE–DATA GOES INTO THE REGISTER SET BY THE
COMMAND BYTE.
7 BITS
DATA BYTE
8 BITS
DATA BYTE–DATA GOES INTO THE REGISTER SET BY THE
COMMAND BYTE.
COUNT= 16
1
10h
device issues a STOP condition (see Figure 6) by transi-
tioning SDA from low to high while SCL is high. A STOP
condition frees the bus for another transmission. The bus
remains active if a REPEATED START condition is gener-
ated, such as in the block read protocol (see Figure 7).
BYTE
WR
0
WR
ACK
0
ACK
ACK
COMMAND BYTE–
REGISTER BEING
WRITTEN.
MSB OF THE
EEPROM
ACK
DATA BYTE
8 BITS
COMMAND
DATA BYTE
8 BITS
...
8 BITS
COMMAND BYTE–
SELECTS REGISTER
BEING WRITTEN.
1
COMMAND
8 BITS
ACK
ACK
ACK
DATA BYTE–FIRST BYTE IS THE LSB OF
THE EEPROM ADDRESS. SECOND
BYTE IS THE ACTUAL DATA.
DATA BYTE
8 BITS
DATA
DATA BYTE
8 BITS
8 BITS
ACK
N
...
ACK
DATA BYTE–DATA GOES INTO THE
REGISTER SET BY THE COMMAND
BYTE IF THE COMMAND IS BELOW
50h. IF THE COMMAND IS 80h,
81h, or 82h, THE DATA BYTE
PRESETS THE LSB OF AN EEPROM
ADDRESS.
8 BITS
DATA
ACK
ACK
8 BITS
DATA
DATA BYTE
8 BITS
ACK
P
ACK
N
P
P
ACK
P